Conventionally, to manufacture a toner container, several types of components are molded from a resin material such as polystyrene in accordance with injection molding, are then filled with toner, and are assembled. To fix the toner on paper or the like, a high temperature of 180° C. to 280° C. and a pressure of 2 kg to 7 kg are applied. In recent years, due to the requirements for energy conservation and higher quality, the particle size of the toner has decreased remarkably, and a heat fusion temperature for the toner has also decreased, so the fixing temperature tends to decrease consequently.
As the nature of the toner changes, two major problems anse. One problem is agglomeration accompanying a particle size decrease of the toner. The higher the temperature and humidity, the more clearly agglomeration occurs. When the toner agglomerates, it causes printing precision degradation such as a change in line width of printed characters. The other problem is as follows. To decrease the fixing temperature, the fusion temperature of the toner itself cannot but be decreased. Hence, when the toner container is exposed to a high-temperature atmosphere, the toner fuses to degrade the printing precision simultaneously.
Conventionally, to prevent a temperature increase in the toner container, the toner container is packaged a number of times. For transport, a temperature-adjustable trailer or the like is used. Also, a fan for decreasing the internal temperature is attached to the main body of a printer or copying machine which is to incorporate the toner container. In either case, however, the cost is high, thus degrading the productivity.